Channel letters are known to those skilled in the art of making commercial signs as the most attractive and expensive form of sign lettering. Briefly, channel letters usually include a plastic or metal backing having the shape of the letter to be formed. Metal channel siding, frequently formed of aluminum with a painted or otherwise finished interior and exterior surface, is attached to and sealed to the letter backing, giving depth to the letter to be formed. Electrical lighting fixtures, such as neon tubing and mounting brackets, are attached to the letter backing. Typically, a colored, translucent plastic letter face is attached to the front edge portion of the channel side material.
As discussed above, neon lighting is typically incorporated into channel lettering systems. Neon systems are very fragile and, therefore, tend to fail and/or break during manufacture, shipping or installation. Also, such lighting systems use high voltage (e.g., between about 4,000 and about 15,000 volts) electricity to excite the neon gas within the tubing. High voltage applications have been associated with deaths by electrocution and building damage due to fire. Semiconductor lighting (e.g., light emitting diodes), that overcomes most of these drawbacks, has been used for channel lettering.
One such conventional channel lettering device attaches a light emitting diode (“LED”) system to a back of a channel letter such that the LED system emits light toward a translucent face at a front of the device. The LEDs are spaced at regular intervals (e.g., 2 inches) and are pressed into a socket. The socket is designed for a press-fit of a modified Super Flux (Piranha) package. The lead frames of the Piranha are bent 90 degrees to fit into the socket. The connection for the LED is similar to insulation displacement (“IDC”). The socket also has two IDC places for a red and black wire. This system puts all of the LEDs in parallel. Furthermore, the two part power supply (Initial (120VAC to 24VDC) and the Secondary (24VDC to ˜2.3VDC)) have two basic wiring connections. The secondary has a sense circuit, which has one LED attached for determining the voltage applied to the rest of the LEDs that are attached to the second connection.
Another conventional channel lettering device attaches to a side of the channel letter and is pointed toward the backing. The diffuse surface of the channel letter walls provides a uniform appearance. Each module has a predetermined number of LEDs electrically connected in series. Furthermore, all of the modules are daisy chained together in a parallel circuit. The LEDs are mounted on an aluminum base for heat sinking purposes.
Another conventional channel lettering device uses a plurality of surface mounted LEDs with an integral connector system.
Although these conventional LED channel lettering systems overcome some of the drawbacks associated with neon systems, other shortcomings are evident. For example, the conventional LED channel lettering systems offer only limited flexibility. More specifically, the LEDs cannot be easily set into a desired shape involving significant curves or bends (e.g., wrapped around a pole or in a very small radius (<3 inches). Furthermore, the LEDs cannot be easily moved from one lighting application to another.
The present invention contemplates an improved apparatus and method that overcomes the above-mentioned limitations and others.